Heifetz was born into a Jewish family inVilnius,Lithuania, then part of theRussian Empire. His father, Reuven Heifetz, was a local violin teacher and served as the concertmaster of the Vilnius Theatre Orchestra for one season before the theatre closed down. Jascha took up the violin when he was three years old and his father was his first teacher. At five he started lessons with Ilya D. Malkin, a former pupil ofLeopold Auer. He was a child prodigy, making his public debut at seven, in Kovno (nowKaunas, Lithuania) playing theViolin Concerto in E minorbyFelix Mendelssohn. In 1910 he entered theSaint Petersburg Conservatoryto study under Leopold Auerhimself.

He played in Germany andScandinavia, and metFritz Kreislerfor the first time in a Berlin private house together with other noted violinists in attendance. Heifetz visited much of Europe while still in his teens. In April 1911, Heifetz performed in an outdoor concert in St. Petersburg before 25,000 spectators; there was such a sensational reaction that police officers needed to protect the young violinist after the concert. In 1914, Heifetz performed with theBerlin Philharmonic conducted byArthur Nikisch.

Heifetz and his family left Russia in 1917, traveling by ship to the United States, arriving in San Francisco. On October 27, 1917, Heifetz played for the first time in the United States, atCarnegie HallinNew York, and became an immediate sensation.In 1917, Heifetz was elected as an honorary member ofPhi Mu Alpha Sinfonia, the national fraternity for men in music, by the fraternity's Alpha chapter at the New England Conservatory of Music in Boston. As he was aged 16 at the time, he was perhaps the youngest person ever elected to membership in the organization. Heifetz remained in the country and became an American citizen in 1925.

Heifetz is considered to be one of the finest violinists of all time. Heifetz's technical command of his instrument -- his physical ability to play the violin with stunning precision -- is regarded by many critics as unequaled. That physical control enabled Heifetz to produce a distinctive tone quality, intense and shimmering, that came to be regarded as his trademark. Yet, from time to time his near-perfect technique and conservative stage demeanor caused some critics to accuse him of being overly mechanical, even cold. His style of playing was highly influential in defining the way modern violinists approach the instrument. His use of rapidvibrato, emotionally chargedportamento, fast tempos, and superb bow control coalesced to create a highly distinctive sound that make Heifetz's playing instantly recognizable to aficionados. The violinistItzhak Perlman, who himself is noted for his rich warm tone and expressive use of portamento, describes Heifetz's tone as like "a tornado" because of its emotional intensity. Perlman also said that Heifetz preferred to be recorded relatively close to the microphone; as a result, one would perceive a somewhat different tone quality when listening to Heifetz during a concert hall performance as opposed to a recording.

In creating his sound, Heifetz was very particular about his choice of strings. He used a silver wound Tricoloregutg-string, plain gut unvarnished D and A strings, and a Goldbrokat steel E string medium including clear Hill brand rosin sparingly. Heifetz believed that playing on gut strings was important in rendering an individual sound.

After an only partially successful operation on his right shoulder in 1972, Heifetz ceased giving concerts and making records. Although his prowess as a performer remained intact and he continued to play privately until the end, his bow arm was affected and he could never again hold the bow as high as before.

Heifetz taught the violin extensively, holding master classes first atUCLA, then at theUniversity of Southern California, where the faculty included renowned cellist Gregor Piatigorskyand violistWilliam Primrose. For a few years in the 1980s he also held classes in his private studio at home in Beverly Hills. His teaching studio can be seen today in the main building of the Colburn School, where it is now used for master classes and serves as an inspiration to the students there.

It was rumored that Heifetz was such a strict discipline observer that the main gate of his Beverly Hills home was closed sharp at the appointment time of his classes to shut out students who arrived late. Heifetz died atCedars-Sinai Medical Centerin Los Angeles, Californiain December 1987.

Heifetz owned the 1714DolphinStradivarius, the 1731 "Piel" Stradivarius, the 1736 Carlo Tononi, and the 1742ex David Guarneri del Gesù, the last of which he preferred and kept until his death. The Dolphin Strad is currently owned by the Nippon Music Foundation. The Heifetz Tononi violin used at his 1917 Carnegie Hall debut was left in his will to Sherry Kloss, Master-Teaching Assistant to Heifetz, with "one of my four good bows" (Violinist/author Kloss wrote "Jascha Heifetz Through My Eyes" and is a co-founder of the Jascha Heifetz Society). The famed Guarneri is now in the San Francisco Legion of Honor Museum, as instructed by Heifetz in his will, and may only be taken out and played "on special occasions" by deserving players. The instrument has recently been on loan to San Francisco Symphony'sconcertmasterAlexander Barantschik, who featured it in concertos with Andrei Gorbatenko and the San Francisco Academy Orchestra in 2006. In 1989, Heifetz received a posthumousGrammy Lifetime Achievement Award.

Heifetz was married in 1928 to the silent motion picture actressFlorence Vidor, ex-wife ofKing Vidor, whose seven year old daughter, Suzanne, Heifetz adopted. The couple had two more children, Josefa (born 1930) and Robert (1932–2001) before divorcing in 1945. In 1947, Heifetz took a sabbatical during which he married Frances Spiegelberg, with whom he had another son, Joseph. The second marriage ended in divorce in 1962.